Since the OP is talking about our current favorite, I'd have to go with Fringe. I really have no words to descibe how amazing I feel whenever I watch it. I love pretty much everything J.J. does and this is a fine example of superb writing.
Spartacus is a close second. Most people who know only a few thing about the show think that its all sex and violence, but if it was only that the show's ratings would have tanked by now. It has brilliant writing and some really good performances (especially by Lucy Lawless as Lucretia).
Games of Thrones is by far a better show than Spartacus and I've thoroughly enjoyed every episode, but still I get way more excited for a new episode of Spartacus.
From comedies I absolutely love Hot in Cleveland, The bing bang theory and Community.
Yes, I do watch more tv than I should...
Btw, I don't remember being more upset about a tvshow getting cancelled than Legend of the Seeker. :(